Meet the 'Von Brats' - the children bringing The Sound Of Music to life.
That's the affectionate name given to the kids on tour with the classic musical, which is half way though its four-week run at the King's Theatre, and also stars Jason Donovan and Verity Rushworth.
In the story Maria might think she has her hands full looking after seven Von Trapp children – but what about dealing with 21?
That's how many seven to 13-year-olds are playing the famous singing family.
The production has three teams of seven children – six to play each of the children and one 'swing' ready to step in to different roles in case of illness.
The seventh Von Trapp, 'sixteen going on seventeen' Liesl, is played by 28-year old Claire Fishenden.
A fourth team of new children has just arrived in Glasgow ready to replace another group leaving the show, which has just celebrated its 50th birthday.
The youngest cast members spend four days with the show then return home for eight days, and they must live within 25 miles of London.
Frank Thompson, 43, resident director and children's director, is in charge of their performances.
While things usually run smoothly, thanks to five weeks of rehearsals, there are some mishaps, especially with the youngest member of the cast, cute little Gretl.
Mr Thompson, originally from Montrose and who appeared in musicals before working as a choreographer and director in the London West End and on Broadway, recalled: "In London we had one Gretl who had an accident on stage – 2500 people at the London Palladium saw it.
"In an opposite scenario another Gretl had to nip off stage to go to the loo mid-scene.
"But we generally like to think we rehearse so much there is no real room for things to go wrong.
"You find the children get to know the show better than we do."
The children are cared for by five chaperones. The kids are staying near the King's and must have at least 15 hours of school lessons a week from a local tutor.
During holidays and weekends they are taken on trips when not performing, with the Science Centre on their list of places to visit in Glasgow.
Sarah Cant, 27, from London, is deputy chaperone and is with the youngsters from dawn until dusk – and often during the night too.
She said: "It's full on. We are their parents away from home. It's always amazing how the young ones settle in.
"Maybe if there is a group of three they have a bicker but we don't have any major problems.
"We have very little tears. You get the occasional phone call in the night saying, 'I miss my mum."
Tom Huttlestone, 13, from Elm Park in London plays Frederich.
He got into performing by doing amateur shows with his mother.
He said: "I was in Oliver! and Joseph And The Amazing Technicolor Dreamcoat in London and a couple of films – Nine, and one about Tony Bair.
"I don't go to stage school, I started doing amateur stuff. I was in Oliver! then we found an agent. I really wanted to do it. It's cool."
Hollie Steel, 12, of Accrington, Lancashire, who made it to the final of Britain's Got Talent a few years ago after crying on live TV after messing up her song, plays Louisa. She goes to the Sylvia Young Theatre School.
She said: "It's fun being away from home – I like the adventure. But I miss my dog Sasha."
Jonathan Loads, 12, from Scarborough, plays Kurt and his parents act as his agents.
One of the youngest is seven-year-old Jasmine Hood, from Hampshire, who has just joined the company.
All the children need costumes – and with six different ones for each child there are 126 in total, coupled with hundreds more for the rest of the cast.
That's not including shoes for fast-growing feet, which run into the thousands.
The tour also takes its own pair of washing machines everywhere.
Wardrobe mistress Trish McAuley, 42, from Manchester, said: "After every show I am washing pants."
Company manager Neil White, 40, from Bradford, is in charge of the actors and crew, said: "Everyone gets used to being upstaged by the kids. It helps that Jason is so child friendly – he has three of his own.
"I'm doing the Oliver! tour next – that has 50 or 60 kids. It's going to be out of the frying pan and into the fire."
The Sound Of Music in numbers:
l 21 children tour with the show.
l 600 kids auditioned.
l 68 people tour with the show, including actors and crew.
l Eight 45ft trucks carry the set and costumes.
l Wardrobe staff spend 8 hours a day ironing.
l A performance involves 115 people on stage and behind the scenes.
l By the time the tour, which started in 2009, ends in October it will have been seen by two million people.
l The show is at the King's Theatre until June 4. For tickets call 08448 717648.